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Work done by the gas during the -

  1. May 10, 2006 #1
    Work done by the gas during the ---

    My son has tried to solve this problem,He is not able to get the answer.Can you please help me to help my son in solving the problem?

    Consider the cyclic process ABCA, shown in the fig.performed on a sample of 2.0 mole of an ideal gas.A total of 1200J of heat is withdrawn from the sample in the process.Find the work done by the gas during the part BC.

    i c.
    i .b
    i .
    i .
    i .
    unable to draw graph. Think of a straight line from pt.c downward on line ob it meets the line at pt.a
    there is a curved line bc.sinking downward.

    can you pl help?(also let me know how to drw diagrams or graphs )
  2. jcsd
  3. May 10, 2006 #2


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    Welcome to PF satishinamdar, We have a section of the forums dedicated to homework and coursework questions. Could you show us what you/your son has attempted thus far? Any working / thoughts? Is the graph a pressure volume curve? If so, the work done is the area encolsed by the curve.

  4. May 11, 2006 #3
    Work done by gas

    I am greatful to receive your reply.
    The attempt made was as follows
    the given graph is a t-v graph
    the work done during CA is 0 as the volume is constant
    therefore work done during the process AB minus work done during the process CB =loss of heat
    as the process is cyclic the change in the internal energy is 0
    AB is straight line from origin hence press is const
    calculating pressure and volume at A as follows
    0.00224m^3 occupy 1 mol of gas at stp and then relating it at 2 mol and 300k and 500k........
    work done at AB is w=p(v2-v1).
    but the answers are not matching ans given in the text book is (-4520joules)
    kindly let me know if i am in the right direction
    Warm Regards
    -tejas inamdar
  5. May 11, 2006 #4
    Work done graph

    I have attached the graph now.
    tejas inamdar
    Last edited by a moderator: May 11, 2006
  6. May 18, 2006 #5
    Dear Sir,
    Kindly help in solving this .
  7. May 18, 2006 #6


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    Your graph isn't attached. I can't see it.
  8. May 22, 2006 #7
    Work done by gas

    jpg .word file attached.

    Attached Files:

  9. May 25, 2006 #8

    Andrew Mason

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    Is this a P-V diagram or a T-V diagram? Since there are no units how do we determine the coordinates of A B and C? If you want us to help, you have to give us all the information. Please write out the complete question. This will include details about the kind of transition between C and B (eg. adiabatic, isobaric), the temperatures at C and one of A or B and the volumes at A and B.

    Last edited: May 25, 2006
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